Aircraft launching and arresting device



Nov. 30, 1965 J. J. BYRNE ETAL 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 12Sheets-Sheet 1 FIG. I

INVENTORS JOHN J. BYRNE 8 ROBERT W CRUGEFZ ATTORNEYS Nov. 30, 1965 J. J.BYRNE ETAL AIRCRAFT LAUNCHING AND ARRESTING DEVICE l2 Sheets-Sheet 2Filed May 4, 1964 N OE JNV EN TORS JOHN J. BYRNE 8 By ROBERT W. CRUGERNov. 30, 1965 J. J. BYRNE ETAL 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 l2Sheets-Sheet 5 PAYOUT INVENTORS JOHN J. BYRNE 8: Y ROBERT W. CRUGEF!Nov. 30, 1965 J, J BYRNE T 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 1,2Sheets-Sheet 4 FIG. 4

INVENTORS JOHN J. BYRNE 8 By ROBERT W. CRUGER W47 IKZRNEYS 1965 J. J.BYRNE ETAL 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 12Sheets-Sheet 5 INVENTORS F|G.6 JOHN J. BYRNE a BY ROBERT W.CRUGERATTORNEYS Nov. 30, 1965 J. J. BYRINE ETAL 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 12Sheets-Sheet 6 INVENTORS JOHN J. BYRNE 8 s ROBERT W. CRUGER ATTORNEYS wQE J. J. BYRNE ETAL 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE l2 Sheets-Sheet 7 ZOELWOAINVENTORS ATTORNEYS Nov. 30, 1965 Filed May 4, 1964 IY m nn Haw Nov. 30,1965 J. J. BYRNE ETAL 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 12Sheets-Sheet 8 FIG. 9 26L POSITION 2 I 24 POSITION INVENTORS Rd E T W gRBgE R FIG. IO BY ATTZZEYS Nov. 30, 1965 J. J. BYRNE ETAL AIRCRAFTLAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 12 Sheets-Sheet 9INVENTORS JOHN J. BYRNE 8| BY ROBERT W. CRUGER ATTORNEYS Nov. 30, 1965Filed May 4, 1964 J. J. BYRNE ETAL AIRCRAFT LAUNCHING AND ARRESTINGDEVICE s9 F|G.l2 85 f 75 l L 5| 73 "IE TIT 12 Sheets-Sheet 10 FIG. I?)

IN V EN TORS JOHN J. BYRNE 6 By ROBERT W. CRUGER ATTORNEYS Nov. 30, 1965J. J. BYRNE ETAL AIRCRAFT LAUNCHING AND ARRESTING DEVICE l2 Sheets-Sheet11 Filed May 4, 1964 INVENTORS JOHN J. BYRNE 6 ROBERT W. CRUGER Jiflw7fWATTORNEYS Nov. 30, 1965 J. J. BYRNE ETAL 3,220,216

AIRCRAFT LAUNCHING AND ARRESTING DEVICE Filed May 4, 1964 12Sheets-Sheet 12 FIG. 20

INVENTORS JOHN J. BYRNE a ROBERT W. CRUGER BY 50127 ffiod ATTORNEYSUnited States Patent 3,220,216 AIRCRAFT LAUNCHING AND ARRESTENG DEVICEJohn J. Byrne, Canton, Ohio, and Robert W. Cruger,

Springfield, Pm, assignors to E. W. Bliss Company, Cauton, Ohio, acorporation of Delaware Filed May 4, 1964, Ser. No. 364,448 3 Claims.(Cl. 24463) This invention relates in general to aircraft launching andarresting means, and more particularly to mechanical and hydraulicrotary energy absorbing engines employed in association with aircraftlaunching and arresting means. This application is acontinuation-in-part of our copending parent application, Serial No.123,527, filed July 12, 1961, now US. Patent 3,142,458, which was inturn a continuation-impart of and copending with our application, SerialNo. 778,723, filed December 8, 1958, now abandoned.

The general scheme for arresting the forward speed of aircraft making alanding on an airstrip, the deck of an aircraft carrier, or the like, isto provide a pendant which is placed transversely across the path of theaircraft to be intercepted by an aircraft hook, or a portion of theaircraft itself. The opposite ends of the pendant are secured to payoutmeans which will permit the pendant to yield with the aircraft and yetat the same time provide predetermined resistance to the aircraftsforward motion of a magnitude sufficient to bring the aircraft to a stopwithin a predetermined distance and in a safe and gradual manner.Although the general increase in aircraft size and landing speeds hasmade our invention necessary, it importance is particularly accentuatedwith the advent of jet aircraft which land at even higher speeds, andrequire even longer runways than heretofore.

In the process of arresting the forward movement of an aircraft, theenergy of motion of the aircraft must be translated into another form,and it is the object of our invention to provide an energy absorbingmeans which operates in a novel and improved manner over presentlyexisting devices for absorbing the energy of landing aircraft. It isanother object of our invention to provide an energy arresting devicewhich is compact, easily transported, installed and operated, and whichis suitable for expeditionary type purposes, as well as commercial use.It is yet another object of our invention to provide an improvedaircraft arresting device which provides resistance to aircraft movementproportional to the speed of the aircraft. It still another object ofour invention to provide a means to modulate the peak to mean load onthe system whereby maximum energy is absorbed when short runwayarrestment is necessary. A further object of our invention is theprovision of a low inertia, high engaging speed, high energy absorber. Astill further object of our invention is the provision of energyabsorbing engines arranged in a novel tandem relationship for increasedenergy absorbing capacity. Yet a still further object of our inventionis the provision of an energy absorbing system adapted to respond tooff-center loading, and pendant engagement permitting a differentialpayout at opposite pendant ends.

Inasmuch as launching and arresting operations as they relate to ourinvention are substantially the reverse of each other, it is yet anotherobject of our invention to ice provide a single mechanism which servesthe dual purpose of both launching and arresting aircraft. Still anotherimportant object of our invention resides in the provision of novelpayout reel and tape means equally adaptable with the severalembodiments of the invention contemplated, disclosed and discussed inthis specification. Another object of our invention resides in theprovision of novel reel and tape means equally advantageous in botharresting and launching functions of embodiments of the invention.Another object of our invention resides in the utilization of a tape ofnovel configuration adapted to permit superior coaction with its reelmeans in both launching and arresting operations. It is still anotherobject of this invention to provide an aircraft arresting engine havingprogramming means adapted to regulate and control force versus runoutrelationships. It is still yet another object of this invention toprovide an aircraft launching and arresting system which can quickly bere-set for substantially continuous operation.

Other objects of our invention will become apparent from a reading ofthe specification, taken in consideration with the drawings and appendedclaims.

FIGURE 1 is a pictorial persepctive view of the general organization ofour invention shown in association with an aircraft in the process ofbeing launched;

FIGURE 2 is a schematic perspective View of a preferred embodiment of alaunching and arresting system employed in the invention;

FIGURE 3 is a side elevatoinal view of the launching and arrestingengine shown in schematic perspective in FIGURE 2;

FIGURE 4 is a front elevational view of the launching and arrestingengine shown in FIGURE 3;

FIGURE 5 is a schematic plan view of the launching and arresting systemshown in FIGURE 2;

FIGURE 6 is a perspective vieW of a tandem arrangement of a launchingand arresting engine embodiment employed for heavy duty arrestingoperations;

FIGURE 7 is a schematic perspective View of another embodiment of alaunching and arresting system employed in the invention;

FIGURE 8 is a side elevational view with parts in section of thelaunching and arresting engine taken on the line 8-8 of FIGURE 9;

FIGURE 9 is a sectional elevational view of the launching and arrestingengine taken on the line 9-9 of FIG- URE 8;

FIGURE 10 is a plan view of a runway showing an aircraft in two stagesof arrestment corresponding to the two stages of reel payout shown inFIGURE 8;

FIGURE 11 is a plan view of a modified embodiment of the launching andarresting system shown in FIGURE FIGURE 12 is an elevational view withparts in section showing the use of a water brake in another preferredembodiment of the invention;

FIGURE 13 is a schematic view of a hydraulic feed and control systemused in conjunction with the water brake shown in FIGURE 12;

FIGURE 14 is a plan view of a synthetic fiber tape employed in apreferred embodiment of the invention;

FIGURE 15 is sectional view taken on the line 1515 of FIGURE 14.

FIGURE 16 is a fragmentary side elevational view taken on the line 1616of FIGURE 14;

FIGURE 17 is a fragmentary sectional view taken on the line 1717 ofFIGURE FIGURE 18 is a schematic representation of the pattern oftransverse strands employed in the tape of FIG- URES 14 through 17;

FIGURE 19 is an elevational view of the means to weave the tape ofFIGURE 14; and

FIGURE is a plan View of the apparatus shown in FIGURE 19.

Although the preferred embodiments of our invention may be used in bothlaunching and arresting operations, indeed this being one of thefeatures of utility of the invention, still the operation of theinventive equipment is somewhat different in launching as compared toarresting. Accordingly, both the aircraft arresting and launchingfeatures of preferred embodiments of the invention will be discussed indetail to provide complete understanding of our inventive concept,

Referring now to the drawings in greater detail, and particularly toFIGURE 1, a typical installation is shown wherein our invention isemployed to launch and arrest aircraft on runways. normally too short toaccommodate planes of a given type, weight, and speed. A runway R isprovided with a runway flush center track. B for guiding a launchingchock C securable to an appropriate appendage D of the aircraft A.Positioned to one side of the runway is to be found one embodiment ofour combination takeup, payoff and energy absorber reel 1, which inlaunching operations is driven by a jet turbine 2 connected to thecombination takeup reel and energy absorber by means of shafting 3 andclutch 4. The installation is controlled by an operator positioned infront of a control panelS conveniently placed ina position of vantagefor viewing the runway. The jet turbine Z'may be of considerably lesscapacity for arresting operations than for combination arresting andlaunching operations, all as will be developed hereinafter.

A flat nylon tape such as shown and described in our Patent No.2,977,076, reissued as Re. 25,406 (which was copending with ourapplication No. 778,723 and which is incorporated in this application byreference), is secured to the combination takeup and payoff reel 1, itbeing also understood that when reference is made to this reel, it iseither a takeup reel or a payoff reel without modification, depending onits function at the moment, whether it be launching, arresting, orrewinding. Accordingly this reel will henceforth be referred to Withoutany further designation as to its capacity.

The reel 1 is adapted to wind and unwind a pair of flat nylon tapes 20Aand B. Nylon tape 20A partially encased in protective conduits 6 and 7,passes betweena pair of sheaves 8A, and then extends down the runway toa fastening device 9A securing the tape to one end of a wirecablependant 12. The other tape passes beneath the runway at F (inprotective conduits not shown, but similar to conduits 6 and '7) andemerges between a pair of sheaves 8B to extend downward of the runwayfor connection by a fastening device 9B to the other end of steelpendant 12.

To launch an aircraft with the above described apparatus, the pilot ofthe aircraft A brings its engine up to speed at the same time thatturbine 2 is brought up to speed, whereupon aircraft restraining meansare released and takeup reel 1 is engaged to the turbine by clutch 3.The nylon tapes 20A and 20B are wound on respective reel spools 22A and2213 until the tapes are entirely rewound, at which time the pendant issubstantially transverse of the runway between sheaves 8A and 8B, andthe aircraft is airborne.

With the steel pendant 12 transverse of the runway R after launching,the system is then automatically in readiness to arrest an aircraftcoming in for a landing. In the arresting operation, suitable pendantintercepting means, such as a hook, landing assemblage or the like (seeFIGURE 2), secured to the aircraft A, engages the steel cable pendant12. After a finite period of time, explained more fully in our reissuedpatent, Re. 25,406, the impact of the aircraft A on the pendant 12causes the nylon tapes 20A and 25-3 to turn reel 1 and thereby pay outthe tape at a substantially constant tension designed to bring theaircraft to a smooth, gentle stop within a predetermined distance.

After the aircraft has been arrested according to plan, the arrestingpendant l2 and nylon tapes have been payed out and are extended from onethousand to several thousand feet down the runway. If it is necessarythereafter to recover this tape and rewind it on the reel preparatory toa subsequent arrestrnent, the jet turbine is then placed into operationto rewind the tape on the reel exactly in the same fashion in which itwas wound when launching aircraft in the manner previously described.Thus, it will become apparent that in both the launching and arrestingfunctions of the apparatus, the jet turbine winds and rewinds the reelin the same angular direction for the same purpose, to-wit: to coil thenylon tape on the reel. The ease and speed with which tape is recoveredon the reel is an important feature of our invention. We havesuccessfully operated our equipment wherein runouts of over one thousandfeet are routinely rewound in less than five minutes without thenecessity of personnel other than the sole operator, and without anyauxiliary equipment. The only other aircraft arresting system actuallyreduced to practice, of which we are aware, requires a crew of about tenmen, two tractors and about forty-five minutes to set up for a secondarrestment.

There is no energy absorbing problem in launching operations inasmuch asall of the energy of the system is expended in getting an aircraftairborne. However, on the arrestment side of the operation, considerableenergy must be dissipated in bringing an aircraft to a stop, and themeans for accomplishing this will now be described.

Reference is made to the drawings in greater detail, and to FIGURE 2 inparticular. An aircraft A is shown making engagement with a pendant 12stretched transverse of the runway R, said aircraft being in the processof arrestment. The opposite ends 16 and 18 of the pendant 12 are securedto a pendant payout means 20, comprising a pair of tapes 20A and 203which are spirally wound on separate spool portions 22A and 22B of reell in such manner that when the reel revolves in the direction of thearrows, the tapes will pay out in opposite directions from the reel topermit the pendant 12 to move with the aircraft down the runway. Spools22A and 22B are coupled with an over-running clutch 22C to permitdifferential angular velocity between the two spools. This isparticularly important during off-center arrestments wherein the onespool is permitted as a consequence to rotate faster than the other. Theresult is therefore a self-compensating adjustment to the center of therunway.

It will be observed that suitable pairs of sheaves 8A, 8B, and 3d aresecured strategically adjacent the runway to guide the payout movementof the tapes 20A and 208. As suggested by FIGURES 2 and 3, this entirereel mechanism may be encased in a pit P beneath the runway, or in theembodiment of an expeditionary system, shown in FIGURE 1, the reel maybe staked out on the surface adjacent to one side of the runway.

In yet another embodiment of expeditionary gear, the spool portions 22Aand 22B may be split and located on opposite sides of the runway R, asshown in FIGURE 11, thereby avoiding the necessity of tunneling beneaththe runway in order to locate tape 20B such as in FIGURE 1. In theembodiment of FIGURE 11 each spool component is a complete reel unit initself, having both a win-dup drive motor 2, and a braking system 23.For purposes of understanding the invention, a complete discussion ofthe embodiment shown in FIGURE 2 will be undertaken, which will alsoexplain the operation of the embodiment shown in FIGURE 11.

Attention is now directed to the hydraulic system of the reel shownschematically in FIGURE 2. A static air-oil reservoir 13 is maintainableunder pressure by means of air pump means 15. Oil is directed throughline 17 to shuttle valve 19. Pressure in branch 17A shifts piston 21 tothe right thereby connecting branch line 17B to brake actuator feederline 21F and brake actuator lines 21L and 21R. In a preferredembodiment, United States Air Force B52 bomber brakes (otherwiseidentified as Bendix brake assembly No. 1,505,556) are used for braking.Thus static brake pressure tank 13 maintains pressure on brakes 23L and23R, which in turn maintains pendant 12 in tension transverse of therunway R, and in readiness for interception by landing aircraft A.

When the pendant is contacted by the aircraft A and shifted to theposition shown in FIGURE 2 in phantom, the pendant payout means 20A and20B rotate the reel 1, which in turn drives hydraulic pump 26, which ischain driven from reel shaft 27. As pump 26 is operated, hydraulic fluidis drawn from pump fluid reservoir 29 through line 31 on the lowpressure side of the pump, through pump 26, and then outwardly on thehigh pressure side of the pump through line 33. Line 37 is tapped fromline 33 at junction 35, and is connected to a normally open valve whichcontrols the return of fluid through line 41 to the brake fluid tank 29.The fluid also is carried in line 43 through check valve 45 to the rightside of spool valve 19. As the fluid pressure builds in the systemcorresponding to the increased velocity of the reel, the static pressureside of the valve 19 applied by line 17A is overcome and the spoolpiston 21 is shifted to connect feeder lines 43F and ZIP to lines 21Land 21R, whereupon the pressure from the pump 26 replaces the staticpressure from static brake pressure tank 13.

It will be apparent therefore that the faster the reel rotates, thegreater will be the pressure developed in brakes 23L and 23R acting toresist rotation. Thus, when the plane is at its greatest velocity aftercontacting the pendant 12, the resistance to forward movement is thegreatest. As the plane is gradually decelerated, the reel, of course,will decelerate, pump 26 will decelerate, and the pressure in brakes 23Land 23R normally would also tend to decrease. To provide for bettercontrol over aircraft deceleration, or to provide adjustment foraircraft of different sizes, a programming device, now to be described,may be included in the system to assure a more constant or predeterminedpressure throughout the period of arrestment.

Programming means comprises a gear box 49 chain driven from reel shaft27 to rotate a cam 51 which in turn operates a cam follower 53 toprogram the opening and closing of a valve 39, and thereby control thepressure in the hydraulic system. One cycle of rotation of the cam 51 isdesigned to provide continuous adjustment in the pressure system duringthe entire runout capacity of the reel. Thus, valve 32 normally open atthe beginning of the arrestment is gradually closed at a predeterminedrate in order to maintain a given pressure, or a controlled rate ofdecline of pressure in the system.

In order to recover the system for a second arrestment a normally closedmanual shutoff valve 55 is opened to relieve the pressure on theoperating pressure side of the spool valve 19 and thereby permit thepressure from the static brake pressure tank 13 to again shift thepiston 21 to reestablish static pressure on the reel brakes. It will benoted that line 43 is also provided with a relief valve 57 which coactswith valve 55 to relieve pressure on the operating side of the valve 21.The heat generated in brakes 23L and 23R may be dissipated with suitablewater jackets surrounding the brakes. So encased, the brakes canfunction effectively even though arrestments are made consecutively inrapid order. Our system has been tested successively wherein arrestmentshave been continuously made as rapid as the tapes 20 and pendant 12could be re-positioned. To this end, a rewind motor 61 drives gear box61A which is chain driven to a sprocket 63 secured to the end of reelshaft 27 opposite from that of the pump and cam driven belt connections.For expeditionary purposes a motor generator set, or a gasoline ordiesel engine may be adapted as a source of power for rewinding the reelafter an arrestment has been made. Of course it will be recognized thatthe power requirements of the motor must be considerably greater if thesystem is to be used for both launching and arrestment. For dualapplication a jet turbine 2 such as shown in FIGURE 1 could besubstituted for motor 61.

Reference is now made to FIGURE 7, wherein is shown a preferredembodiment of the invention utilized for arrestments of shorter distancethan contemplated for the embodiment of FIGURE 2. Because of therelatively short runout, it is observed that only a single reel 22 maybe employed. An aircraft 10 is shown in FIGURE 7 making engagement witha pendant 12 stretched across runway 14, and said aircraft is in theprocess of being brought to a stop. The opposite ends 16 and 18 of thependant 12 are secured to a pendant payout means 20, preferably nylontape, as aforesaid. The tape 20 is spirally wound upon a reel 22 so thatwhen the reel revolves in the direction of the arrow 23, the tape willpay out in opposite directions from the reel to permit the pendant 12 tomove with the aircraft down the runway. Suitable sheaves 24 are providedwhere needed to guide the movement of the payout tape 20.

As is shown more clearly in FIGURES 8 and 9, the reel 22 is providedwith a pair of gears 25 positioned on opposite sides of the reel. A pairof hydraulic pumps 26L and 26R are mounted on the reel housing 28 (seeFIGURE 9) and are drivingly connected to pinion gears 30 in meshedengagement with gears 25. A reel drive motor 32 is also provided and isdrivingly connected to gear 25 by means of pinion gear 34 in meshedengagement with ring gear 24. As in the case of the embodiment of FIGURE2 the horsepower rating of the rewind motor '52 will depend on whetherthis embodiment of the invention is to be used for the dual function ofboth launching and arresting, or for arrestment alone. The drive shaft36 of the motor 32 is coupled with the shaft 38 of pinion gear 34 bymeans of a sliding coupling 40 which is locked to motor drive shaft 36by pin means 42. Hydraulic brake means 23L and 23R are provided onopposite sides of reel 22 and journaled on reel shaft 46 with respect tothe portion rotating with reel 22. The stationary portion of the brakemeans is secured to reel frame 28 wherein are provided hydraulicconnecting means 48 adapted to actuate the brakes.

Referring back to FIGURE 7, pumps 26L and 26R are connected to developpressure in a hydraulic system, generally designated at 48. A staticpressure fluid reservoir 54 is connected by a standpipe 56 to bothhydraulic brake assemblies 23L and 23R in order to maintain a constantminimum static pressure on the brake assembly and thus a slight amountof tension on the pendant 12, and payout means 21). As indicated by thearrows associated with the hydraulic system 48, in addition torecirculation of hydraulic fluid by pump 26R to and from reservoir 52through lines 50, 55 and 59, fluid is also pressurized in line 51connected to brake assembly 23R. In like manner, pump 26L, in additionto recirculating hydraulic brake fluid to and from reservoir 52, throughlines and 5?, also pressurizes line 53 to sensing cylinder 61), which isinterposed between the reservoir 52 and brake assembly 23L.

A normally open shuttle valve 57 is placed at one end of line 51 betweenlines and 56 to permit static pressure between reservoir 54 to beapplied to the right brake 23R through line 51 while at the same timerestricting line 55 on the high pressure side of the right pump 26R.When the right pump 26R is actuated by rotation of the reel 22, thepressure from the pump overcomes the static pressure acting on thepiston of shuttle valve 57, and

7 shifts this piston to allow pump pressure to be applied to the brakethrough line 51. With pump 26R thus in operation, pressure from staticreservoir 54 is cut off to brake 23R, and fluid is slowly metered bymeteringvalve 61R to reservoir 52 at such a rate as to maintain apredetermined pressure within the system.

In like manner, a normally open shuttle valve 63 is interposed betweenline 67 and line 56 to permit static pressure from reservoir 54 to reachthe left brake 23L while blocking'line 67. When the left pump 26L isactuated, pressure from the pump through line 53 acting on the sensingcylinder piston 66 relays pressure through line 67 to shuttle valve 63whose piston then shifts to block line 56 to reservoir 54-, and allowssensing cylinder pressure to react on the brake 23L through line 56. Ametering valve 61L is disposed in line 59 between lines 53 and 55 toprovide and maintain any desired operating pressure on this side of thesystem.

For a better understanding of-the function and construction of thesensing cylinder 66, reference is now made again to FIGURE 8. It will berecognized that when a friction type disk assembly, such as employedwith this embodiment of the invention, becomes heated due to coaction ofone disk against the other, the coefiicient of friction of the brakewill correspondingly change, likewise static and high running speedcoefiicients of friction are not the same. Nevertheless, a uniformretarding load is desirable throughout the engagement of the aircraft,and the sensing cylinder, as will be described more fully hereinbelow,acts to proportionately decrease the brake pressure as the coefficientof friction of the brake disks increases and vice versa.

Hydraulic brake fluid is received from pump 261. at port 62 to exertpressure against the end 64 of piston 66. This pressure is transmittedby piston 66 to port 68 which in turn is connected to line 67, thepressure therein actuating brake 23L. The piston 66 is provided with afollower sheave 70 adapted to make engagement with payout tape 20 and tosense the tension in the payout tape. Thus, as the reel rotates, therebycausing the pump 26L to apply pressure to brake 23L, the tension in tape2% increases. The tape tension is sensed by sensing cylinder 6% in thata thrust is applied against follower sheave 79 to force the piston 66inwardly. As piston 66 is moved inwardly, pressure in line 67 isrelieved to a degree wherein the tape tension is then proportional tothe pump pressure. If the coefficient of friction in brakes 23L and 23Ris higher than normal, the tension in the tape, and the consequent forcevector acting on the sensing cylinder follower sheave 70, is increasedforcing the piston as inwardly to reduce the brake line 67 pressure,thereby decreasing the amount of braking, and relieving the tension inthe tape iii). If the coefi icient of friction in brakes 23L and 23R islower than normal, the tension in the tape and force on the sensingcylinder follower sheave is decreased, and piston 66 moves outwardly toincrease the pressure in line 67 acting on the brake 23L.

This is a very sensitive mechanism and is responsive to slight changesin coefficient of friction with the net effect of modulating oraveraging such changes to provide a smooth constant deceleratinginfluence on the landing aircraft. The payout tape 20 is shown in twopositions on the reel 22 to illustrate that the angle of wrap about thesensing follower sheave 7t) is less at the start of the payout as shownby the aircraft in FIGURE 10, position 1, than is the angle of wraptoward the end of the payout when the aircraft is at position 2. It willbe recognized that the resultant component of force acting against thepiston 66 increases as the angle of wrap of tape 2% increases.

When longer runways are available and/ or heavier aircraft landing athigher speeds must be arrested, the embodiment of our invention shown inFIGURE 6 is applicable. Herein we have shown a series of arrestingengines with dual tape reels to increase the energy absorbing capacityof the system and yet maintain a relatively small size unit. The reelsshown in tandem are provided with pairs of spools 72 and 74. The spoolsidentified by the numeral 72 are adapted to permit a payout of tapesZtiA to the left as shown in FIGURE 6, and the spools identified bytheir numeral 74 are adapted to provide a payout of tapes 2M3 to theright. This arrangement then retains the features of low inertia whichpermit high engaging speeds such as are inherent in the single reel em,-bodiment of the invention already described. The tandem arrangementprovides for greatly increased energy absorbing capacity. Each spool isconnected to its mating spool by means of an overrunning clutch 22Carrangement of any conventional design well understood. in the art,whereby if an unexpected or excessive demand is placed on one side ofthe system as compared to the demand on the opposite side, such asdeveloped by offcenter engagement, the high demand side of this systemwill be permitted to slip or yield in order to provide the extra payoutwhich this side of the system is demanding. This clutch construction issubstantially identical to that employed with the embodiment of theinvention shown in FIGURE 2, and of course may be installed similar tothe arrangement shown in FIGURE 11, wherein tandem spools 72 may belocated on one side of the runway and tandem spools 74'n1ay be locatedon the opposite side in lieu of the single spools shown in FIGURE 11.

Reference is now made to FIGURES l2 and 13 wherein is illustrated yet athird embodiment of our invention in which we employ the principles of awater brake for the same purposes as set forth and described heretoforewith respect to the embodiments of FIGURES 2 and 7.

Generally stated, a water brake within the concept of our invention, isa hydro-dynamic device that absorbs power by converting mechanicalenergy into heat in its working liquid medium, this liquid mediumnormally being water. Resistance is created exclusively by fluidfriction and agitation of the water circulated between vaned pockets ofthe rotor and stator elements, with the conversion of mechanical energyinto heat taking place directly within the water itself. The amount ofmechanical energy that can be absorbed in this manner is dependent uponthe quantity and velocity of the water in the working chamber.

Reference is now made more specifically to FIGURE l2 wherein a typicalwater brake 69 is shown partially in section. Water from inlet 71 passesdirectly into supply chambers 73 in each of housings 75 of the stator77. From the stator supply chamber 73, water enters into each side ofthe working chamber 79.

The revolving speed of the water brake 69 under any load condition iscontrolled by the quantity of water in its working chamber 79. Asrtheload varies, a constant revolving speed may be maintained by varying thestatic head 95 in the circulating system (see FIGURE 13) and statorsupply chambers 73, or the volume of water entering the brake inletwhich governs the quantity of water in the Working chamber. When therotor is revolved in the direction to create resistance, the water inthe rotor vaned pockets 87 moves to the outer ends of the pockets bycentrifugal force where it is forced across into the vaned pockets 89 ofthe stator 77. As the vaned pockets 89 of the stator 77 are filled, thewater in them is forced back across into the rotor vaned pockets 87 atthe innermost point; and this cycle is repeated as long as the brake isrevolved in a direction to create resistance. The fluid friction andagitation that thereby results develops a resistance against therevolving rotor 85 that converts the mechanical energy into heat in thewater.

It will be readily seen that with any specific quantity of water in theworking chamber, the velocity of the water circulated back and forthbetween the vaned pockets 87 and S9 of the rotor 85 and stator 77respectively will be increased with the increased angular velocity ofthe rotor 85 with resultant increased fluid friction and agitation. Inthis manner, the horsepower capacity of the water brake increasesapproximately in proportion to the cube of its speed. If the speed isdoubled, the horsepower resistance is increased eight times. Thus, therevolving speed limitation of the rotor is mechanical, but thehorsepower capacity of the brake increases with speed in the above ratioto the maximum possible operating speed based on the physical capacityof the bake structure.

For our purposes, however, it is enough to analogize the similaritybetween the water brake embodiment of our invention, and embodiments ofour invention wherein a fluid medium is acted upon in direct proportionto the angular velocity of the reel to apply braking effort against reelrotation. Thus, in the first two embodiments of our invention alreadydiscussed, rotation of the reel drives a hydraulic pump which in turnpressurizes a hydraulic system designed to apply hydraulic force againsta mechanical brake. In the water brake embodiment of our invention, therotor 85 is the hydraulic pump, and the stator 77 is the brake, suchthat the faster the reel is rotated, the greater will be the coactionbetween the pump 85 and the brake 77 to resist reel rotation. Therefore,it follows that in all embodiments of our invention, a hydraulic pump isan element of the combination, which acts against a brake, whether it befluid or mechanical, in proportion to the velocity of the reel, therotation of which provides energy for the hydraulic pump.

Reference is now made to FIGURE 13, wherein is shown a schematicrepresentation of a typical circulating and control system for the waterbrake embodiment 69 of our invention. A valve 91 is provided in thesupply line 93 leading from a static head 95 to the water brake 69.Valve 91 is adapted to control the rate at which water can enter thewater brake. This control is obtained in a manner quite similar to theprogramming means described relative to the brake system shown in FIGURE2. For instance, a gear box 49 is chain driven to reel shaft 97 and isselected to rotate cam plate 51 one revolution per cycle of arrestment.Thus cam follower 53 is secured to gate or throttle means in valve 91for controlling the flow of water therethrough. The valve capacity isadjusted proportional to the need for maintaining a given tension on theaircraft. When the reel is rotating at a high angular velocityproportionately less water is required for coaction between thehydraulic pump rotor 85 and the hydraulic brake stator 77. However, asthe angular velocity of the reel decelerates, or higher tension isrequired, valve 91 is proportionately opened to permit an increased rateof flow of water into the water brake 69 sufiicient to maintain thedesired tension on the tapes 20A and 20B.

Although programming means are not essential to successful aircraftarrestment by any of the embodiments of our invention, it is a usefulcontrol feature. In addition to providing tension control duringarrestment, it is also very useful in adjusting the system for runoutsof different lengths, as well as for providing means for adjusting forarrestment of different weight aircraft, wherein the runout may be thesame, but the programmed tension requirements may differ. It followstherefore that various combinations of runout and tension controladjustments are possible with our programming means.

We consider of particular significance and importance to the successfuloperation of all embodiments of our invention discussed and disclosedherein the coaction and configuration of the reel and tape. Heretoforethey have been touched upon generally, but specifically the advantagesof our design will now be discussed in greater detail. We consider it tobe particularly important that the tape be of a flat, wide bandconfiguration wherein the width is great compared to the thickness ofthe tape sufficient to permit the tape to spirally wind and unwind uponitself concentrically layer upon layer. This is a distinct departure, tothe best of our knowledge, from all prior art reeling mechanisms,wherein the material being wound on a reel is not amenable to coilbuilding upon itself. For instance, with wound material such as wirecable, it is necessary to traverse the cable back and forth along theaxis of rotation of the reel in order to build layers which aresufficiently stable to provide reliability in winding and unwindingoperations. This method of reel winding is practically universal inapplication and, prior to our invention, was the only method for windinga payout element on a reel.

Now, however, by resorting to our novel configuration of tape, severaladvantages become apparent upon consideration. In the first place, it ispossible with our tape configuration to impart suflicient strength tothe synthetic fiber to enable the withstanding of the high forces oftension to which the fibers must be subjected. Additionally, theconfiguration of the tape lends itself to ease of handling andreliability in winding and unwinding, such that there is practically nopossibility of fouling of the tape on the reel. This becomes readilyapparent in view of the fact that there is no wedging action betweenadjacent turns of the tape such as is inherent in wire cable woundpayout reels. Additionally, linking, overlapping, binding and most otherdisadvantages of cable wound reeling are eliminated by our tapeconfiguration.

Another and important benefit resides in using fiat wide tape which canbe coiled radially by laminating one layer of tape concentrically uponanother. This benefit is found in a moment arm mechanical advantagewhich operates to increase the efficiency of the system, regardless ofwhether the apparatus is employed in launching or arresting operations.

Reference is now made to FIGURES 14 through 17 which illustrate theweave of the tape which we have adopted for use in our invention. Itwill be observed that the tape comprises a plurality of longitudinallyaligned load bearing strands 170, transversely bound together by astrand 172 passing from one side surface to the other side surface ofsaid tape, as well as from edge to edge across the width of the tape. Inaddition to the longitudinal strands and the transverse strands 172,smaller longitudinal strands 174- adjacent to longitudinal strands 170extend longitudinally (FIGURE 14) and from top to bottom of the tape(FIGURES l5 and 17) to lock the top surface of the tape to the bottomsurface. Thus, longitudinal strands 170 function as load bearing membersin the tape, transverse strands 172 function to hold the tape conformityfrom side to side, and longitudinal strands 174 function to maintainconformity in the tape from top to bottom.

FIGURE 18 schematically illustrates the path of weave of the transversetape 172 as it passes from side to side. FIGURES 19 and 20 illustratethe manner in which the tape is woven. It will be seen herein that aplurality of spools of monofilament yarns 176 are mounted on a creel 178and each strand from each spool is fed into a bobbin assembly 180mount-ed on the wrapper 182. The finished tape 160 passes over an idlerroll 184 and is wound on reel 185. The technique of weaving the tape,not being the subject of this invention, will not be discussed in anyadditional detail inasmuch as these methods are well known to thoseskilled in the textile arts.

We employ drawn nylon for our tape, but recognize that other synthetlcfibers can also be use-d such as rayon, for instance, and we furtherrecognize that with the rapidly advancing technology of synthetic fibersstill other fibers will eventually be developed which may prove to be ofeven greater utility than nylon. However, a high tensile strengthsynthetic fiber is required because of its resistance to moisture, rot,mildew, and

11 adverse effects of weather, and because of the superior strengthsobtainable in synthetic fibers over those of natural fibers.

Consider first an arresting operation. The tape is fully wound on a reelspool such that the moment arm from the outer layer of the tape to theaxis of the rotation of the reel is at its greatest at the instant thatthe pendant is engaged by the aircraft. The result is that the coactionbetween tape and reel is at its maximum mechanical advantage in order toset the system in motion with the least force. Additionally, thisconcept of fiat tape, wide in relation to its thickness so as to becapable of being spirally wound on a reel in a single stack ofconcentric layers, is inherently capable of being designed to provide asmooth non-pulsating payout. Tape thickness, reel and spool diameter,and torque requirements are of course variables which can and must bedetermined on an individual basis by engineers skilled in the art tomeet demands expected to be imposed on a particular installation. To ourknowledge, no other arresting or launching system, prior to our concept,has this inherent capability. Thus in a correctly designed system,constructed in accordancewith our teaching, as the tape pays out themoment arm progressively decreases such that the torque applied to thesystem by the momentum of the aircraft is proportionately reducing atthe same rate as the aircraft deceleration. However, because theeffective diameter of the reel decreases as the tape is payed out, thereel angular velocity tends to remain substantially constant. Sincebrake resistance is proportional to reel velocity, the tape tensionacting on the aircraft is maintained relatively constant. The combination of reel and tape, therefore can be analogized to a velocitysensitive gear reduction system, or continuously variable transmissionto provide aircraft retarding force responsive to changes in aircraftvelocity.

Considering now a launching operation, the tape is initially payed outto its full length wherein the minimum moment arm of the reel issubstantially equal to onehalf the radius of the reel drum. However, inthis situation, the forces are reversed and it is the reel which mustpull the aircraft rather than the aircraft which is pulling the reel asin arrestment operation. Thus, it is highly important that initially themoment arm of the reel be small in order to obtain the greatest possibleturning effort in assisting aircraft to overcome its inertia of rest.However, once the aircraft is in motion and is being brought up tospeed, the torque requirements on the reel become progressively reducedat the same time that reel speed must progressively increase. This isautomatically provided by our tape which is win-ding upon itself anddeveloping a moment arm of ever-increasing radius such that when theleast torque and highest speed is required of the reel the torque hasbeen reduced to its lowest level approximately at the time the aircraftbecomes airborne. Thus, of all of the novel features and advantages ofour developments, we consider the coaction of our novel tape and reel tobe of primary importance to the successful operation of our invention.

It is to be understood that whereas several embodiments of our inventionhave been described hereinabove, these embodiments are by way of exampleonly and are not to be construed in a limiting sense. It is recognizedthat other arrangements and modifications will readily occur to thoseskilled in the art upon reading the specification and the attachedclaims taken in conjunction with the included drawings. These otherarrangements and modifications if based upon the teaching of ourinvention are intended to be covered within the spirit and scope of theappended claims.

What is claimed is:

1. For aircraft launching and/or arresting gear of the class describedincluding a runway pendant having a high modulus of elasticity adaptedto be engaged by an aircraft, a rotary-type pendant payout means and aninterconnecting means between said pendant and payout means: anexpendable replacement article of manufacture for use as saidinterconnecting means comprising a tape composed of a multiplicity oflongitudinally aligned load-bearing synthetic fiber strands extendingthe entire length of the tape, a plurality of layers of said strandsextending across the thickness of said tape, woven together withtransverse strands passing from one side surface to the other sidesurface of said tape, as well as from edge to edge across the width ofsaid tape, said longitudinal strands including external strands andinternal strands, each of said external strands lying on one sidesurface only of said tape andeach of said internal strands lying whollywithin the body of said tape and encased Within said external strands,there being a plurality of layers of said internal strands lying throughthe thickness of said tape between pairs of said external strands onrespective sides of. said tape, said tape having a modulus of elasticitysubstantially less than said pendant but of sufficient strength towithstand the high forces of tension to be sustained, said tape having aflat, wide band configuration wherein the width is great compared to thethickness thereof and adapted to permit said tape to spirally coil bylaminating one layer of tape concentrically in ever-increasing diameterupon a reel during winding and unwinding, free from kinking, overlappingand binding, the thickness of said tape being predetermined, in relationto its width and the said tension forces to provide a maximum reelmoment arm when said coil' of tape is fully wound on said reel, saidmoment arm progressively decreasing as said tape is unwound from saidreel, whereby said tape provides, during the said launching andarresting operations, a cooperative co-action with said reel, providingmaximum mechanical advantage to set the system in motion with the leastforce.

2. For aircraft launching and/or arresting gear of the class describedincluding a metal runway pendant having a high modulus of elasticityadapted to be engaged by an aircraft, a rotary-type pendant payout meansand an interconnecting means between said pendant and payout means: anexpendable replacement article of manufacture for use as saidinterconnecting means comprising a tape composed of a multiplicity oflongitudinally aligned load-bearing nylon fiber strands extending theentire length of the tape, a plurality of layers of said strandsextending across the thickness ofsaid tape, woven together withtransverse strands passing from one side surface to the other sidesurface of said tape, as well as from edge to edge across the width ofsaid tape, said longitudinal strands, including external strands andinternal strands, each of said external strands lying on one sidesurface only of said tape and each of said external strands lying whollywithin the body of said tape and encased within said external strands,there being a plurality of layers of said internal strands lying throughthe thickness of said tape between pairs of said external strands onrespective sides of said tape, said tape having a modulus of elasticitysubstantially less than said pendant but of sufiicient strength toWithstand the high forces of tension, said tape having a fiat, wide bandconfiguration wherein the width is great compared to the thicknessthereof and adapted to permit said tape to spirally coil by laminatingone layer of tape concentrically in ever-increasing diameter upon a reelduring winding and unwinding, free from kinking, overlapping andbinding, the thickness of said tape being predetermined, in relation toits width and the tension forces to be sustained, to provide a maximumreel moment arm when said coil of tape is fully wound. on said reel,said 13 '14 inoment arm progressively decreasing as said tape is un-References Cited by the Examiner wound from said reel, whereby said tapeprovides, dur- UNITED STATES PATENTS ing the said launching andarresting operations, a 2,540,874 1 51 GeddingS 133 411 cooperativeco-action with said reel, providing maXi- 2,742,059 4/1956 Watts 139411mum mechanical advantage to set the system in motion 5 OTHER REFERENCESwith the least force- Aviation Week, Sept. 23, 1957, pages 86, s7, s9,91,

3. The article of manufacture of claim 2 further com- 93 95 97 99prising a plurality of longitudinally extending strands, I I in additionto said load-bearing longitudinal strands, and MILTON BUCHLER PrlmwyExamme' which pass from top to bottom of the tape to further 10 FERGUSMIDDLETON, Examiner- Inaintflin Conformity thefeof- L. C. HALL,Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,220,216 November 30, 1965 John J. Byrne et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 2, line 23, for "persepctive" read perspective line 29, for"elevatoinal" read elevational same column 2, line 62, after "is" inserta column 9, line 9, for "bake" read brake column 12, line 55, for"strands," read strands lines 57 and 58, for "external" read internalSigned and sealed this 18th day of October 1966.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner ofPatents

1. FOR AIRCRAFT LAUNCHING AND/OR ARRESTING GEAR OF THE CLASS DESCRIBEDINCLUDING A RUNWAY PENDANT HAVING A HIGH MODULUS OF ELASTICITY ADAPTEDTO BE ENGAGED BY AN AIRCRAFT, A ROTARY-TYPE PENDANT PAYOUT MEANS AND ANINTERCONNECTING MEANS BETWEEN SAID PENDANT AND PAYOUT MEANS: ANEXPENDABLE REPLACEMENT ARTICLE OF MANUFACTURE FOR USE AS SAIDINTERCONNECTING MEANS COMPRISING A TAPE COMPOSED OF A MULTIPLICITY OFLONGITUDINALLY ALIGNED LOAD-BEARING SYNTHETIC FIBER STRANDS EXTENDINGTHE ENTIRE LENGTH OF THE TAPE, A PLURALITY OF LAYERS OF SAID STRANDSEXTENDING ACROSS THE THICKNESS OF SAID TAPE, WOVEN TOGETHER WITHTRANSVERSE STRANDS PASSING FROM ONE SIDE SURFACE TO THE OTHER SIDESURFACE OF SAID TAPE, AS WELL AS FROM EDGE TO EDGE ACROSS THE WIDTH OFSAID TAPE, SAID LONGITUDINAL STRANDS INCLUDING EXTERNAL STRANDS LYING ONONE NAL STRANDS, EACH OF SAID EXTERNAL STRANDS LYING ON ONE SIDE SURFACEONLY OF SAID TAPE AND EACH OF SAID INTERNAL STRANDS LYING WHOLLY WITHINTHE BODY OF SAID TAPE AND ENCASED WITHIN SAID EXTERNAL STRANDS, THEREBEING A PLURALITY OF LAYERS OF SAID INTERNAL STRANDS LYING THROUGH THETHICKNESS OF SAID TAPE BETWEEN PAIRS OF SAID EXTERNAL STRANDS ONRESPECTIVE SIDES OF SAID TAPE, SAID TAPE HAVING A MODULUS OF ELASTICITYSUBSTANTIALLY LESS THAN SAID PENDANT BUT OF SUFFICIENT STRENGTH TOWITHSTAND T HE HIGH FORCES OF TENSION TO BE SUSTAINED, SAID TAPE HAVINGA FLAT, WIDE BAND CONFIGURATION WHEREIN THE WIDTH IS GREAT COMPARED TOTHE THICKNESS THEREOF AND ADAPTED TO PERMIT SAID TAPE TO SPIRALLY COILBY LAMINATING ONE LAYER OF TAPE CONCENTRICALLY IN EVER-INCREASINGDIAMETER UPON A REEL DURING WINDING AND UNWINDING, FREE FROM KINKING,OVERLAPPING AND BINDING, THE THICKNESS OF SAID TAPE BEING PREDETERMINED,IN RELATION TO ITS WIDTH AND THE SAID TENSION FORCES TO PROVIDE AMAXIMUM REEL MOMENT ARM WHEN SAID COIL OF TAPE IS FULLY WOUND ON SAIDREEL, SAID MOMENT ARM PROGRESSIVELY DECREASING AS SAID TAPE IS UNWOUNDFROM SAID REEL, WHEREBY SAID TAPE PROVIDES, DURING THE SAID LAUNCHINGAND ARRESTING OPERATIONS, A COOPERATIVE CO-ACTION WITH SAID REEL,PROVIDING MAXIMUM MECHANICAL ADVANTAGE TO SET THE SYSTEM IN MOTION WITHTHE LEAST FORCE.